Flue starting plate



April 19 1955 c. l.. MccREA 2,706,395

FLUE STARTING PLATE Filed Dec. 8. 195o vif-'1111.11 P1/I:

INVENTOR ATTORNEYS' United States Patent FLUE STARTING PLATE Charles L. McCrea, Washington, D. C.

Application December 8, 1950, Serial No. 199,852

1 Claim. (Cl. 72-95) The present invention relates to improvements in flues and particularly relates to ue starting plate structures.

It is the primary object of the invention to provide a ue starting plate structure for attachment to the ceiling joists of a building to support thereon a rectangular ue casing and to also support a cylindrical ue pipe disposed centrally within said flue casing. Further objects of the invention may be best understood with reference to the following description and to the accompanying drawing and appended claim.

The present application is a continuation-in-part of my copending application, Serial No. 139,346, led January 19, 1950, now abandoned.

In the drawing, in which the same parts are denoted by the same reference numerals throughout the several views,

Figure 1 is a fragmentary elevational view of structure including an embodiment of the present invention;

Figure 2 is a fragmentary view of a section of the flue of Figure 1;

Figure 2A is a fragmentary view of a connection arrangement;

Figure 3 is a perspective view of the ue starting plate structure of the present invention;

Figure 4 is a detailed view taken along the line 12-12 of Figure 1, and

Figure 5 is a detailed view of a pipe connection.

Referring to Figure 1, there is shown a flue generally made up of a plurality of casing sections designated generally by the reference numeral 110 within which are sections of flue pipe 111. The casing structure is arranged to be supported upon joists 54 and to extend through the roof of the building where it projects into the dummy chimney 42, and at the lower end of the flue there is attached a suitable T structure 37. The support at the joists 54 consists of a starting plate structure indicated generally as 112.

The individual casing sections 110 may be best understood with reference to Figure 2. In this view it will be observed that each casing section 110 consists of four side panels 114, 116, 118 and 120. These panels are preferably made of sheet metal such as galvanized iron, and may be made from a single sheet of metal by bending at three corners and fastening at the fourth corner, or there may be two or more sheets fastened accordingly at the necessary number of corners. Any conventional corner fastening arrangement will be suitable. "ll`wo sides of the section 114 and 118 are bent slightly outward at their upper ends as at 122 to form a suitable engagement with the next section, as will be described more fully below. At their lower ends these just mentioned sides 114 and 118 are bent slightly inward as at 124 to correspondingly provide engagement with the next lower section. The two remaining sides 116 and 120 have both their upper and lower edges bent outwardly and then parallel to lie alongside the side panels so that a drive strap may be employed to maintain two adjoining sections together.

With the understanding that each of the sections 110 will be identical, it will nowrbe apparent that two of the sections 110 may be joined together by first hanging an S-shaped joining strip over the upper edges of sides 114 and 118 of the lower section and then seating the lower edges of these sides of the upper section within the lower groove of the S-strips. The details of this connection may be fully understood from the fragmentary view in Figure 2A. In Figure 2A the S-strip designated as 126 2,706,395 Patented Apr. 19, 1955 "ice is shown with the adjoining edges of sides 114 in place in the grooves of the strip.

By thus combining the previously described drive strap connections with the S-strip connections, a rigid joint is provided between sections which will not tend to telescope, notwithstanding the absence of the abutting horizontal end plates 16 and 17 of the first described embodiment.

Within the chamber formed by the side walls 114, 116, 118 and 120, there are positioned lateral flue pipe supporting plates 128. Preferably, there will be tWo of these plates for each section and they will be spaced inwardly from the upper and lower ends of the section 110. Each of the plates 128 may be fastened to the side plates in any suitable manner, as by welding to angle brackets or the like. Each of the lateral supporting plates 128 has a circular central aperture 130 of a diameter just large enough to receive the sections of cylindrical cement-type pipe 111 employed as the inner flue pipe member. Each lateral supporting plate 128 also has formed therein venting apertures 132, as shown in Figure 2.

Before proceeding with a description of the assembled flue, the starting plate 112 will next be described. Referring now primarily to Figure 3, the starting plate 112 consists of a horizontal base plate 134 of square or rectangular outline. The four edges of the base plate 134 are bent upwardly and the corners suitably fastened together to form a box-like structure open at the top. These four upturned edges are designated as 136, 138, and 142. The central portion of the base plate 134 is extended downwardly to form a cylindrical sleeve 144. This sleeve is of a diameter just sufficient to receive the end of the length of cement-type pipe 111 which forms the inner flue. An annular shoulder 146 extends inwardly from the lower end of sleeve 144 to provide a seat upon which the ue pipe may rest, and a further sleeve 148 is then arranged to extend downwardly from the inner edge of shoulder 146 to provide a male joining mtriber for connection of the previously mentioned T The starting plate 112 is adapted for mounting on the joists 54 by means of elongated supporting members in the form of angle irons 150 and 152 which are attached to upturned edges 138 and 142 of the starting plate. These angle irons may be fastened by any suitable means such as welding to the just mentioned edges in such position that the horizontal flange of the angle iron extends outwardly level with the top of the edges 158 and 142. These angle irons extend beyond the starting plate 112, as best shown in Figure l, so that nails or screws may be inserted upwardly through the horizontal anges and into the joists 54. In addition to the supporting angle irons 138 and 142, there may also be provided relatively exible metal straps 154. These straps may be suitably attached to the upturned edges 136 and 140 of the starting plate by any suitable means such as riveting or welding. These straps may then be tightened over the tops of joists 54 and in this manner will aid in supporting the starting plate and will further serve to prevent the angle irons 138 from becoming loose on the joists 54. The depth of the edges 136, 138, 140 and 141 is selected so that the base section 134 will be located the required distance below the joists 54 to provide a plaster ground. Accordingly, the starting plate structure serves both as a means for supporting the llue and as a ground for plastering the finished ceiling of the heater room.

The starting plate 112 is also provided with venting apertures 156, similar to the previously mentioned venting apertures 132 in the lateral supporting plates 128.

The flue will normally be assembled in the building by first locating the proper position for the starting plate 112 and then proceeding to fasten the angle irons 150, 152 and the straps 154 to the joists 54. It may be noted here that the flue is preferably square and it is immaterial whether the joists 54 run parallel to or at right angles to the roof joists 52.

After the starting plate 112 is in place, the lowermost section 110 is inserted into the startign plate 112. The

manner in which the section 110 seats in the starting plate 112 may be best understood with reference to Figure 4. A drive strap connection between the lowermost section 110 and the starting plate 112 is not necessary and, therefore, the section 110 may be slightly modified by straightening the lower edges of side panels 114 and .113 and also by straightening the lower drive strap flanges of side panels 116 and 120 so that they extend directly down to seat within the upturned edges of starting plate 112.

After the lowermost section 116 is in position the first section of flue pipe 111 may be lowered into place by passing it through the apertures 130 in the lateral supporting plates 128 until the lower end of the pipe seats on the shoulder 146. The pipe 111, as previously mentioned, may be of a cement type, such as asbestos cement. Pipe of this character is commercially available under the name Transite. The upper end of the lowermost pipe section 111 will be beveled as indicated in Figure 5 and a pipe coupling collar 158 is placed around this beveled end of pipe 111. After collar 158 is in place, the next higher section 110 is joined to the lowermost section 110 by means of two S-strips 126 and two drive straps, as previously explained.

The necessary number of combined pipe and casing sections are assembled according to the above procedure until the uppermost section extends through the roof and into the dummy chimney. The top of the uppermost flue section should extend a few inches above the high side of the opening in the roof sheathing. It is intended that the height of the dummy chimney will be so related to the length of the Hue sections that the necessity of adding another flue section will never result in the added flue section interfering with the uppermost structural portions of the dummy chimney. That is, whenever the uppermost flue section does not reach this minimum distance, another section may be added and yet the added section will not exceed the usable length of the dummy chimney. This arrangement also means that the flue sections never need to be cut down in the field.

The inner liuc pipe 111 may be extended from the uppermost coupling collar 158 to the top 43 of the dummy chimney by means of a sheet metal smoke pipe, such as pipe 41. However, this may be yet another length of cement-type pipe if desired.

From the foregoing description it will be appreciated that in the preferred embodiment of my invention a cement-type inner flue pipe may be employed together with a ventilated air chamber. It will further be appreciated that a cement-type flue pipe may be readily supported by my novel starting plate 112 without resort to bolts or the like extending into the pipe and the starting plate also serves as a plaster ground. These are very important features of my invention because it is difficult and time consuming to support this type of pipe in any presently known manner and to plaster around known supporting arrangements.

Those familiar with the problems involved in providing reasonably priced housing at present day prices will immediately appreciate that my invention embraces very important improvements in the flue art. First of all, iioor space is at a premium in small houses, and by use of my iiue supported on overhead joists, up to five square feet of floor space are saved for the usual furnace and water heater. If a brick iiue is employed according to known practices, it must start at the ground and will occupy some of the area of the building. Moreover, all of the components of my flues may be readily mass-produced, with the result that the cost of an installed flue is much less than any other type of flue constructed at the place of installation. In addition, my tiues meet the safety 4 requirements of the Underwriters Laboratories and every type of municipal ordnance with which I am familiar.

As an important example of meeting safety requirements, the automatic location of the starting plate relative to the bottom of the joists not only provides a plaster ground but also locates the T structure at a proper distance (usually specified by the Underwriters and/or by Code) below the ceiling. In this way, the person in the iield installing the flues is not called upon to exercise his judgment as to a proper clearance from the ceiling.

It is obvious that various changes and modifications may be made in the details of construction and design of the above specifically described embodiment of this invention without departing from the spirit thereof, such changes and modifications being restricted only by the scope of the following claim.

I claim:

A sheet metal flue starting plate structure for supporting a rectangular flue section and for supporting a cylindrical tlue pipe disposed centrally therein, said starting plate structure comprising a substantially fiat base section, upturned edges extending from the base section along each side of said section forming a rectangular well for receiving said rectangular ue section, a cylindrical extension formed centrally in said base section and extending downwardly from the base section, an inwardly extending annular shoulder formed at the lower end of said cylindrical extension, a second cylindrical extension of lesser diameter than the first cylindrical extension extending from the inner edge of said annular shoulder and further in a direction downward from the base section, the first cylindrical extension being arranged to receive said cylindrical flue pipe, the said annular shoulder being arranged to receive and support the end of said cylindrical flue pipe, the second cylindrical extension forming means for receiving a pipe extending from a heating furnace or the like for feeding flue gases into said cylindrical ue pipe, and elongated supporting members attached to one pair of opposite upturned edges and extending beyond the limits of said upturned edges for spanning and for connection to the undersides of adjacent building joists from which the starting plate with the flue parts assembled thereon is to be supported, said elongated members having a portion attached to said upturned edges, and another portion for attachment to said joists, the arrangement being such that prefabricated, uniformly sized and constructed ue starting plates in accordance with the foregoing recitations can be expeditiously installed without modification or adaptation to the underside of joists of any spacing greater than the dimensions of said rectangular flue section and not greater in spacing than the length of said elongated supporting members.

References Cited in the file of this patent UNITED STATES PATENTS 268,860 Browell Dec. 12, 1882 285,112 Clawson Sept. 18, 1883 376,478 Hentzell Jan. 17, 1888 973,777 Grissom Oct. 25, 1910 1,328,647 Carl Jan. 20, 1920 1,342,918 Legg June 8, 1920 1,429,822 Acer Sept. 19, 1922 1,578,030 Hirschberg Mar. 23, 1926 2,150,891 Tennison Mar. 14, 1939 2,181,074 Scott Nov. 21, 1939 2,372,707 Blome Apr. 3, 1945 2,457,470 Howle Dec. 28, 1948 2,592,084 Van Alstyne Apr. 8, 1952 

